Improve package-check-signature docstring

* lisp/emacs-lisp/package.el (package-check-signature): Improve
docstring.

diff --git a/lisp/emacs-lisp/package.el b/lisp/emacs-lisp/package.el
index 812e1eb0ff73aed96d11ee676cc517ae7fa27198..4268f7d27a728d9ec12d777d705494c447961bcf 100644 (file)
--- a/lisp/emacs-lisp/package.el
+++ b/lisp/emacs-lisp/package.el
@@ -346,21 +346,28 @@ default directory."
 
 (defcustom package-check-signature 'allow-unsigned
   "Non-nil means to check package signatures when installing.
-More specifically the value can be:
-- nil: package signatures are ignored.
-- `allow-unsigned': install a package even if it is unsigned, but
-  if it is signed, we have the key for it, and OpenGPG is
-  installed, verify the signature.
-- t: accept a package only if it comes with at least one verified signature.
-- `all': same as t, except when the package has several signatures,
-  in which case we verify all the signatures.
 
 This also applies to the \"archive-contents\" file that lists the
-contents of the archive."
+contents of the archive.
+
+The value can be one of:
+
+  t                  Accept a package only if it comes with at least
+                     one verified signature.
+
+  `all'              Same as t, but verify all signatures if there
+                     are more than one.
+
+  `allow-unsigned'   Install a package even if it is unsigned,
+                     but verify the signature if possible (that
+                     is, if it is signed, we have the key for it,
+                     and GnuPG is installed).
+
+  nil                Package signatures are ignored."
   :type '(choice (const :value nil            :tag "Never")
                  (const :value allow-unsigned :tag "Allow unsigned")
                  (const :value t              :tag "Check always")
-                 (const :value all            :tag "Check all signatures"))
+                 (const :value all            :tag "Check always (all signatures)"))
   :risky t
   :version "27.1")